Stories tagged sound

Over on the New Scientist's Short Sharp Science blog there is a great little experiment to try. Mix up some hot chocolate and tap your spoon on the bottom of the mug. As you do this the pitch of the tapping sound will change. Why? They don't know yet either. Any guesses?

Nov
03
2006

All week, the comic strip "Non Sequitur" has been running gags about whether or not a duck's quack echoes. The joke is that once someone asks you the question, you can't stop thinking about it until you know the answer. It's Friday, and I've resisted the temptation to look it up until now, but I've caved!

I can't think of a single scientific reason why a duck's quack WOULDN'T echo, but I had to look it up anyway. The good news? I'm hardly the first person to do it. When I googled "Does a duck's quack echo?" I got 105,000 hits, including links to some real research.

Here are some of the best sources of info:

BBC news: "Sound science is quackers"

Salford University: "The duck's quack echo myth" (This is an awesome page.)

The Straight Dope: "Is it true a duck's quack won't echo?"

Science Made Simple: Does a duck's quack echo?"

About.com (Urban Legends and Folklore): "A duck's quack doesn't echo"

MadSci Network: "Why won't the quack of a duck echo?"

SPOILER: Yes, a duck's quack, like any other sound, echoes. But the WAY a duck quacks, with the long "AAAAAACK" sound at the end of the call, tends to mask echoes, making them hard to hear.

Sep
16
2006

Loud this time of year: Fork-tailed bush katydid (Photo courtesy Jenn Formann Orth)
Loud this time of year: Fork-tailed bush katydid (Photo courtesy Jenn Formann Orth)

This article, by Tyler Rushmeyer, appeared in the local news section of today's Pioneer Press:

Racket bugging residents: Night music made by katydid colony
Many White Bear Lake residents were baffled when they started hearing a new sound reverberating through their neighborhoods.
As night falls, a loud "yack, yack" sound has filled the air. "It sounds like a tropical rainforest on my block," said White Bear Lake resident Mark Nevala, one of several people to call city officials asking about the noise.
The culprit: katydids, loud insects performing mating calls by rubbing their wings together. The mating season should last into early October.
Closely related to grasshoppers and crickets, katydids are spread throughout Minnesota. The bugs residents are hearing are the northern katydid species, said Dick Oehlenschlager, assistant curator and collections manager for biology at the Science Museum of Minnesota.
"They move in colonies and shift every year, and this year their colony seems to have taken residence in the Twin Cities area," he said.
The insects--about 2 inches long and bright green, with long, coiled antennae--are near-motionless during the day and reside on the leaves of trees. But soon after dusk, they become active. They are difficult to spot, Oehlenschlager said, which is why many people are confused about where the noise is coming from.
"Even I didn't know what I was hearing the first couple times I came in contact with them," Oehlenschlager said.

Look for our new fall phenology section, featuring other seasonal behaviors of insects and birds, coming to the Mississippi River Gallery and the Buzz website after next week.

May
23
2006


What's my name?: Researchers have found out that dolphins create their own series of clicks and whistles to identify themselves much like the names we give ourselves. (Photo by sandor at morguefile.com)
You’ve got your Donald Duck, Mickey Mouse and Rocky the Squirrel. How about Diane the Dolphin?

The May edition of National Geographic reports that marine biologists have discovered that dolphins give themselves a unique name to identify themselves among their peers. It might not sound like our first names such as “Bob” or “Lisa,” but rather is a unique combination of whistles and clicks that single them out among the other dolphins in their group.

So how do scientists know this for sure? Afterall, there aren’t any humans who can speak dolphin, right?

The idea that dolphins have their own unique sounds for their name dates back in theory to 1991. But only recently have researchers been able to test out those ideas.

What they’ve done is take audio recordings of dolphin sounds collected over the past 30 years. Focusing their efforts on bottle-nosed dolphins found around Sarasota, Fla., researchers mimicked those recorded sounds with sounds made through keyboard synthesizers and then played back that new audio to the dolphins through underwater speakers.

What they discovered was that the Florida dolphins responded strongly to the sounds that were copies of sounds from other dolphins in their group and largely ignored the sound patterns from unfamiliar dolphins.

Furthermore, researchers also believe that young dolphins begin honing their listening skills, and developing their own unique vocal identification, early in life. It’s an especially important skill for bottle-nose dolphins since they live in large packs in sometimes murky waters. With a much more advanced social structure than other types of animals, dolphins may need to have better ways of finding each other when their separated.

Other interesting twists to the dolphin naming practices:

• Male dolphins are likely to choose a pattern of sound that is similar to their mother’s name sound.
• Dolphins love their names. Researchers have determined that they’ll say their names a lot when communicating with other dolphins, for instance saying “Diane caught a fish.”
• Other dolphins will mimic a peer’s name sound patterns to get that dolphin’s attention.

More information about dolphin naming practices can be found at http://news.nationalgeographic.com/news/2006/05/060508_dolphins.html

And for all you football fans reading this, there’s no word in the research if any new dolphins have taken the name Daunte.

Nov
15
2005


Singing Mouse Photo

Researchers at Washington University in St. Louis have discovered that mice sing.

Scientists already knew that mice make ultrasonic sounds-squeaks that are too high-pitched for us to hear without special equipment. But these scientists used microphones and computer software to study the squeaks of 45 male mice.

What's in a song?

The researchers separated the squeaks into types of syllables based on how quickly the pitch rose or fell. The mice "sang" about 10 syllables per second. And almost all of the mice repeated sequences of syllables in clear patterns. None of the mice are Marvin Gaye, exactly, but their noises meet the scientific definition of song. (People, birds, whales, and some insects do the same thing.)

Why sing?

Researchers still have to figure out WHY the mice sing. Because the mice sang in response to pheremones-chemicals that transmit messages between animals of the same species-one guess is that male mice sing to impress females.

Hear the mice singing.